Hard code config values that may lead to network instability

[cmwaters]

We had some nodes report the following error:

1:04PM ERR Stopping peer for error err="received message exceeds available capacity: 1900008 < 1900544" module=p2p peer={"Data":{},"Logger":{}} 

This comes about because some nodes have a MaxTxBytes set to 1.9MB and others to 7.9MB. This difference means that some transactions get accepted to some mempools but not to others.

Proposal

Hard code config values that may lead to network instability. Specifically this means to hardcode MaxTxBytes. There may be other parameters we may want to consider